Anhydrous antiperspirant aerosol composition

Abstract

Anhydrous antiperspirant aerosol compositions comprising antiperspirant active, urea, non-ethanolic carrier oil and volatile propellant, said compositions delivering good perspiration reduction and humectancy, without valve blockage of associated hardware.

The invention claimed is: 
     
       1. A base composition for an antiperspirant aerosol comprising:
 a) less than 0.1% by weight of free water, 
 b) 20 to 50% by weight of antiperspirant active that is an aluminium halohydrate salt, 
 c) 2 to 15% by weight of urea, and 
 d) 35 to 65% by weight of a non-ethanolic carrier oil selected from the group consisting of silicone oils, alkyl ether oils, triglycerides, ester oils, and mixtures thereof, 
 wherein the non-ethanolic carrier oil is a water insoluble organic material that is liquid at ° C., 
 
       wherein the base composition is free of ethanol and further wherein the base composition has a viscosity of less than or equal to 10000 cPs (mPa·s) measured at ° C. using a Brookfield Viscometer 24 hours after sample preparation, using a T A  spindle, at 10 rpm, and further wherein urea possesses a % change in mass value measured at 37° C. and 90% relative humidity using Dynamic Vapour Sorption instrument greater than or equal to the value for PEG-4. 
     
     
       2. The base composition according to  claim 1 , comprising 3 to 12% by weight of urea. 
     
     
       3. The base composition according to  claim 1  having a viscosity of between 2500 and 7500 cPs (mPa·s). 
     
     
       4. The base composition according to  claim 1 , wherein the aluminium halohydrate salt is aluminium sesquichlorohydrate having a chemical formula Al 2 OH 4.4 Cl 1.6  to Al 2 OH 4.9 Cl 1.1  and further comprising water-soluble calcium salt and amino acid. 
     
     
       5. The base composition according to  claim 1 , wherein the non-ethanolic carrier oil is a volatile silicone oil. 
     
     
       6. The base composition according to  claim 1 , further comprising a suspending agent. 
     
     
       7. The base composition according to  claim 6 , wherein the suspending agent comprises hydrophobically modified clays. 
     
     
       8. The base composition according to  claim 1 , comprising 30 to 50% by weight of antiperspirant active. 
     
     
       9. The base composition according to  claim 1 , wherein the aluminium halohydrate salt comprises aluminium chlorohydrate, activated aluminium chlorohydrate, activated aluminium sesquichlorohydrate or a mixture thereof. 
     
     
       10. The base composition according to  claim 1 , wherein the antiperspirant active is activated. 
     
     
       11. The base composition according to  claim 1 , comprising 45 to 65% by weight of non-ethanolic carrier oil. 
     
     
       12. The base composition according to  claim 1  having a viscosity of between 2600 and 7000 cPs (mPa·s). 
     
     
       13. The base composition according to  claim 1  having a particle size not greater than 125 μm. 
     
     
       14. The base composition according to  claim 1  having a particle size not greater than 100 μm.